littoral zone

marine ecological realm that experiences the effects of tidal and longshore currents and breaking waves to a depth of 5 to 10 metres (16 to 33 feet) below the low-tide level, depending on the intensity of storm waves. The zone is characterized by abundant dissolved oxygen, sunlight, nutrients, generally high wave energies and water motion, and, in the intertidal subzone, alternating submergence and exposure. The geological nature of shorelines and nearshore bottoms is exceedingly varied. Consequently, the littoral fauna taken as a whole involves an enormous number of species and every major phylum, although the number of individuals may vary widely with locality. Coral reefs, rocky coasts, sandy beaches, and sheltered embayments each possess specialized, intricately interrelated floral and faunal littoral populations